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中间加代理，通过代理做授权和控制

## 示例

科学上网  
明星经纪人

```js
// 发布者（Publisher）
const publisher = {
  subscribers: [],

  // 添加订阅者
  addSubscriber(subscriber) {
    this.subscribers.push(subscriber);
  },

  // 发布事件
  publishEvent(event) {
    this.subscribers.forEach(subscriber => {
      subscriber.receiveEvent(event);
    });
  }
};

// 订阅者（Subscriber）
const subscriber1 = {
  receiveEvent(event) {
    console.log('Subscriber 1 received event:', event);
  }
};

const subscriber2 = {
  receiveEvent(event) {
    console.log('Subscriber 2 received event:', event);
  }
};

// 添加订阅者到发布者
publisher.addSubscriber(subscriber1);
publisher.addSubscriber(subscriber2);

// 发布事件
publisher.publishEvent('Hello, subscribers!');

```
